DOUBLE-BLIND, RANDOMIZED COMPARISON OF ONDANSETRON AND INTRAOPERATIVEPROPOFOL TO PREVENT POSTOPERATIVE NAUSEA AND VOMITING

Background: Breast surgery is associated with a high incidence of post operative nausea and vomiting. Propofol and prophylactic administratio n of ondansetron are associated with a lower incidence of postoperativ e nausea and vomiting. To date no comparison of these two drugs has be en reported. A randomized study was done to compare the efficacy of on dansetron and intraoperative propofol given in various regimens. Metho ds: Study participants included 89 women classified as American Societ y of Anesthesiologists physical status 1 or 2 who were scheduled for m ajor breast surgery. Patients were randomly assigned to one of four gr oups. Group O received 4 mg ondansetron in 10 ml 0.9% saline and group s PI, PLP, and PP received 10 ml 0.9% saline before anesthesia inducti on. Group O received thiopental, isoflurane, nitrous oxide-oxygen, and fentanyl for anesthesia. Group PI received propofol, isoflurane, nitr ous oxide-oxygen, and fentanyl. Group PIP received propofol, isofluran e, nitrous oxide-oxygen, and fentanyl. Thirty minutes before expected skin closure, isoflurane was discontinued and 50 to 150 mu g . kg(-1). min(-1) propofol was given intravenously to maintain anesthesia. Grou p PP received propofol for induction and maintenance of anesthesia, ni trous oxide-oxygen, and fentanyl. Postoperative pain relief mas provid ed with morphine administered by a patient-controlled analgesia pump. The incidence of nausea and vomiting, requests for rescue antiemetic a nd sedation, pain scores, and hemodynamic data were recorded for 24 h. Results: Within 6 h of surgery, groups O and PP had a lower incidence of nausea compared with groups PI and PIP (P < 0.05). Fewer patients in group PP (19%) vomited during the 24-h period compared with groups O (48%), PI (64%), and PIP (52%) (P < 0.05). The incidence of antiemet ic use was also less in group PP (P <: 0.05). Patients in group PP had lower sedation scores at 30 min and at 1 h (P < 0.05). There were no differences among the groups in pain scores, blood pressure, heart rat e, respiratory rate, and incidence of pruritus. Conclusions: Propofol administered to induce and maintain anesthesia is more effective than ondansetron (with thiopental-isoflurane anesthesia) in preventing post operative vomiting and is associated with fewer requests for rescue an tiemetic and sedation in the early phase of recovery. It is equally ef fective in preventing postoperative nausea as ondansetron in the first 6 h after operation. Propofol used only as an induction agent or for induction and at the end of surgery were not as protective against pos toperative nausea and vomiting.